This chapter explores the links between modern migration and long-standing transhumance movements in Mauritania. In the country, livestock farmers have for a long time practiced internal and cross-border transhumance, to optimize access to water and pasture. This has allowed them to cope with harsh environmental conditions. However, in recent decades, transhumance has been affected by challenges such as climate change and violent conflicts. As a result, livestock farmers have abandoned it and are instead migrating to the urban centres. Mauritania’s economic hubs are also magnets for regional migrants, mostly from other West African countries. This chapter draws on data collected through IOM’s Displacement Tracking Matrix